The present invention relates to aqueous fabric care compositions for use in a wash or rinse bath which provide improved benefits to treated fabrics. More particularly, the present invention relates to fabric care compositions containing a polycarboxylate polymer with a urea-derived compound, which compositions impart to the treated fabric improved benefits relating to moisture absorption, fragrance deposition, soil removal, reduced wrinkling prior to ironing and better appearance after ironing.
Fabric care compositions which provide softening in the wash cycle or rinse cycle of automatic laundry washing machines or in an aqueous wash/rinse bath are well known in the art. While these fabric care compositions are generally recognized as providing very good softening properties to treated fabrics, they nevertheless have certain drawbacks in terms of adversely affecting the treated fabrics with regard to properties such as moisture absorption, fragrance deposition and wrinkling of the fabric prior to ironing.
Starch and starch solutions are well known compositions to aid in removing wrinkles during ironing from fabrics which have been previously washed/rinsed using a variety of commercial laundry fabric care compositions. The use of such starch solutions, however does not overcome the aforementioned drawbacks associated with the use of commercial fabric softening compositions.
Polyacrylate type polymers have been incorporated into detergents for a variety of benefits. Typically, polyacrylate type polymers provide a cleaning benefit in detergents due to increased dispersancy of soil in the wash water, and due to inherent builder properties of such polymers. These types of polymers generally do not deposit on the fabric surface.
In an effort to improve the crease resistance and stain resistance of fabrics, U.S. Pat. No. 5,879,749 describes the use of a fabric treatment composition which contains a poly-functional molecule, such as derived from polyacrylic acid, in combination with a urea-derived compound. During pressing or ironing of the fabric, the urea-derived compound is said to crosslink the poly-functional molecule and thereby provide crease resistance to the fabric.
A class of polymers that are known to deposit out of the wash liquor onto the fabric surface are referred to as soil release polymers. These polymers are typically polyethylene terephalate/polyoxyethylene terephalate polymers that deposit on fabric, preferentially polyester fabrics. They act to make the surface more hydrophilic, so that oily soils may be more easily removed. However, the benefit of such polymers is limited to soil release, and even that benefit is limited primarily to polyester-containing fabrics.
The use of polycarboxylates in fabric softener compositions is known. U.S. Pat. Nos. 4,043,965; 3,993,830 and 3,821,147 assigned to Colgate-Palmolive describe softener compositions containing a polyacrylate polymer to provide soil release benefits. The described compositions are maintained at a pH of below 3 so as to render the polymer insoluble when added to the rinse bath allowing it to deposit on the fabrics.
Accordingly, there is no recognition in the prior art of being able to deposit a polyacrylate-based material out of a wash or rinse liquor onto a fabric surface over a broad range of pH so as to provide a wide variety of significant fabric care benefits to treated fabrics, unrelated to detergency.
The present invention provides an aqueous fabric care composition for use in the wash or rinse cycle of a washing machine for cleaning or softening of fabrics concomitant with providing improved benefits to treated fabrics relating to moisture absorption, fragrance deposition, soil removal, reduced wrinkling prior to ironing and better appearance after ironing, said composition comprising:
(a) from about 0.1% to about 30%, by weight, of a surfactant selected from the group consisting of anionic, nonionic and cationic surfactants, and wherein said surfactant is not derived from hydrazine;
(b) from about 0.1% to about 5% by weight of (i) a polymer derived from a polycarboxylic acid; and (ii) a compound derived from urea; and
(c) balance water and adjuvants.
The present invention is predicated on the discovery that the use of the fabric care compositions of the invention in an aqueous wash bath or rinse bath, enables an effective amount of the polymer and urea-derived compound to deposit on the fabric surface and thereby provide the aforementioned fabric care benefits to the treated fabric. In contrast with the prior art which exemplifies applying a fabric treatment solution containing a polyacrylic acid polymer but in the absence of surfactant directly to the fabric by spraying with a pump or aerosol spray, the present compositions are able to effect deposition on fabric in the wash cycle or rinse cycle of a washing machine. Although applicants do not wish to be bound by any theory of operation, it is believed that the presence of a surfactant in the compositions of the invention serve a two-fold purpose: it facilitates deposition of polymer out of the wash or rinse bath and onto the fabric; and it provides improved fabric care benefits which have heretofore not been provided or appreciated using conventional fabric treating compositions.
It is believed that prior to ironing the fabric, the urea-derived compound does not crosslink (the crosslinking reaction being heat activated) but the polymer/urea-derived compound composition nevertheless is able to provide reduced wrinkling of fabric prior to ironing. It is hypothesized that the reduction in wrinkling is due to preferential hydrogen bonding between the polymer/urea-derived compound composition and the cellulose fibers of the cotton fabric, as opposed to intra-cellulose fiber hydrogen bonding. The intra-cellulose fiber hydrogen bonding, following distortion of the fabric geometry during washing/rinsing, is part of the mechanism for wrinkle formation. By reducing the level of intra-cellulose fiber hydrogen bonding by use of the present invention, the number of wrinkles that remain in fabric as it dries is significantly reduced.
Finally, during ironing of the fabric, the urea-derived compound is activated. The urea-derived compound then bonds together the polymer chains, forming a stiff film on the fabric surface. This is believed to effectively keep the fabric in the conformation it is forced into via ironing.
The polymers useful for the present invention are derived from a polycarboxylic acid. They can be prepared by polymerizing or copolymerizing suitable unsaturated monomers, preferably in their acid form. Unsaturated monomeric acids that can be polymerized to form suitable polymers include but are not limited to acrylic acid, methacrylic acid, maleic acid (or maleic anhydride), fumaric acid, itaconic acid, aconitic acid, mesaconic acid, citraconic acid and methylenemalonic acid.
Particularly suitable polymeric polycarboxylates can be derived from acrylic acid. Such acrylic acid-based polymers which are useful herein are the water-soluble salts of polymerised acrylic acid. The average molecular weight of such polymers in the acid form preferably ranges from 2,000 to 10,000, more preferably from 4,000 to 7,000 and most preferably from 4,000 to 5,000. Water-soluble salts of such acrylic acid polymers can include, for example, the alkali metal, ammonium and substituted ammonium salts. Soluble polymers of this type are known materials.
Acrylic/maleic-based copolymers may also be used. Such materials include the water-soluble salts of copolymers of acrylic acid and maleic acid. The average molecular weight of such copolymers in the acid form preferably ranges from 2,000 to 100,000, more preferably from 5,000 to 75,000, most preferably from 7,000 to 65,000. The ratio of acrylate to maleate segments in such copolymers will generally range from 30:1 to 1:1, more preferably from 10:1 to 2:1. Water-soluble salts of such acrylic acid/maleic acid copolymers can include, for example, the alkali metal, ammonium and substituted ammonium salts. Soluble acrylate/maleate copolymers of this type are known materials which are described in EP 193,360 published Sep. 3, 1986.
The compounds of the present invention are derived from urea. The preferred compounds for use herein are derived from urea and contain at least two hydroxyl groups. The hydroxyalkyl ureas (HAU) such as N,N-bis(2-hydroxyethyl)urea are especially preferred. Exemplary HAU compounds include, but are not limited to, N,N-bis(2-hydroxyethyl)urea, tetrakis(2-hydroxyethyl)urea, tris(2-hydroxyethyl)urea, N,Nxe2x80x2-bis(2-hydroxyethyl)urea, N,Nxe2x80x2-bis(3-hydroxypropyl)urea, N,Nxe2x80x2-bis(4-hydroxybutyl)urea and 2-urea-2-ethyl-1, 3-propanediol.
The compositions of the invention can be used in the wash cycle or rinse cycle of an automatic laundry washing machine or in an aqueous wash bath or rinse bath during hand laundering.
When used in a rinse bath or in the rinse cycle of a laundry washing machine, the compositions contain a cationic surfactant fabric softener, excluding hydrazine derivatives.
The fabric softening compound which is useful in the compositions of the invention is a fabric substantive quaternary ammonium compound or an amine compound suitable for conditioning fabrics.
A preferred softening compound is a biodegradable fatty ester quaternary ammonium compound of Formula II: 
wherein each R4 independently represents an aliphatic hydrocarbon group having from 8 to 22 carbon atoms, R5 represents (CH2)sxe2x80x94R7 where R7 represents an alkoxy carbonyl group containing from 8 to 22 carbon atoms, benzyl, phenyl, (C1-C4)-alkyl substituted phenyl, OH or H; R6 represents (CH2)t R8 where R8 represents benzyl, phenyl, (C1-C4) alkyl substituted phenyl, OH or H; q, r, s and t, each independently, represent a number of from 1 to 3; and x is an anion of valence a.
The fatty ester quaternary compounds are preferably diester compounds, i.e. R7 represents benzyl, phenyl, phenyl substituted by C1-C4 alkyl, hydroxyl (OH) or hydrogen (H). Most preferably R7 represent OH or H, especially preferably OH, e.g. R5 is hydroxyethyl.
q, r and s, each, independently, represents a number of from 1 to 3.
X represents a counter ion of valence a. For example, the diester quat may be a compound of the formula: 
where each R4 may be, for example, derived from hard or soft tallow, coco, stearyl, oleyl, and the like. Such compounds are commercially available, for example, Tetranyl AT1-75, from Kao Corp. Japan, which is di-tallow ester triethanol amine quaternary ammonium methyl sulfate. Tetranyl AT1-75 is based on a mixture of about 25% hard tallow and about 75% soft tallow. A second example would be Hipochem X-89107, from High Point Chemical Corporation.
Another preferred fabric softening compound is an amido (or ester) tertiary amine which is an inorganic or organic acid salt of Formula (III): 
wherein R1 and R2 independently represent C12 to C30 aliphatic hydrocarbon groups, R3 represents (CH2CH2O)pH, CH3 or H; T represents NH; n is an integer from 1 to 5, m is an integer from 1 to 5, and p=1 to 10.
R3 in formula (III) represents (CH2CH2O )pH, CH3, or H, or mixtures thereof. When R3 represents the preferred (CH2CH2O)pH group, p is a positive number representing the average degree of ethoxylation, and is preferably from 1 to 10, especially 1.4 to 6, and more preferably from about 1.5 to 4, and most preferably, from 1.5 to 3.0. n and m are integers of from 1 to 5, preferably 1 to 3, especially 2. The compounds of formula (III) in which R3 represents the preferred (CH2CH2O)pH group are broadly referred to herein as ethoxylated amidoamines (when Txe2x95x90NH) or ethoxylated ester amines (when Txe2x95x90O), and the term xe2x80x9chydroxyethylxe2x80x9d is also used to describe the (CH2CH2O)pH group.
Most especially preferred is the compound of formula (III) which is commercially available under the tradenames Varisoft 512 (a 90% concentration with a 10% organic solvent), or Varisoft 511 (approximately a 100% active ingredient concentration), available from Witco Chemical Company, which is bis(tallow-amidoethyl)-hydroxyethyl amine of the following formula 
In the non-neutralized (non-protonated) form the fatty amide or fatty ester tertiary amine compounds are hardly or not at all dispersible in water. Therefore, in the present invention, the amine function of the amidoamine or ester amine compound is at least partially neutralized by a proton contributed by a dissociable acid, which may be inorganic, e.g., HCl, H2SO4, HNO3, etc. or organic, e.g. acetic acid, propionic acid, lactic acid, citric acid, glycolic acid, toluene sulfonic acid, maleic acid, fumaric acid, and the like. Mixtures of these acids may also be used, as may any other acid capable of neutralizing the amine function. The acid neutralized compound is believed to form a reversible complex, that is, the bond between the amine function and proton will disappear under alkaline pH conditions. This is in contrast to quaternization, e.g., with a methyl group, wherein the quaternizing group is covalently bonded to the positively charged amine nitrogen and is essentially pH independent.
The amount of acid used will depend on the xe2x80x9cstrengthxe2x80x9d of the acid; strong acids such as HCl, and H2SO4 completely dissociate in water, and, therefore, provide a high amount of free protons (H+), while weaker acids, such as citric acid, glycolic acid, lactic acid, and other organic acids, do not dissociate completely and, therefore, require a higher concentration to achieve the same neutralizing effect. Generally, however, the amount of acid required to achieve complete protonation of the amine, will be achieved when the pH of the composition is rendered strongly acidic, namely between about 1.5 and 4. HCl and glycolic acid are preferred, and HCl is especially preferred.
Furthermore, the amount of acid used for neutralization should be sufficient to provide at least a 0.5:1 molar ratio, and up to about a 1:1 molar ratio of the acid to the total amount of fabric softener fatty amide or ester tertiary amine. For the organic carboxylic acids, however, it is preferred to use a molar excess of the neutralizing acid. Molar ratios of organic carboxylic acid to the compound of formula (III) up to about 6:1, for example from 1.5:1 to 6:1, such as 2:1, 3:1 or 4:1, have been found advantageous in terms of stability and/or softening performance. The use of glycolic in molar excess is especially preferred.
Another preferred class of fabric softening compound for use herein is the class of compounds known as alkyl quaternary amines, commonly referred to as xe2x80x9cquatsxe2x80x9d by those skilled in the art. Other softening compounds which are known to those skilled in the art may also be included in the fabric care compositions for purposes of the invention.
The emulsifier used in the present fabric softening compositions is required to stabilize the composition and prevent phase separation. The fatty alcohol ethoxylates useful for this purpose correspond to ethylene oxide condensation products of higher fatty alcohols, with the higher fatty alcohol being of from about 9 to 15 carbon atoms and the number of ethylene oxide groups per mole being from about 10 to 30. In the preferred fatty alcohol ethoxylates for use herein, the alkyl chain length ranges from about 13 to 15 carbon atoms and the number of ethylene groups ranges from about 15 to 20 per mole. Especially preferred for use herein is Synperonic A20 manufactured by ICI Chemicals, such nonionic surfactant being an ethoxylated C13-C15 fatty alcohol with 20 moles of ethylene oxide per mole of alcohol and having an HLB of 8.25.
When used in a wash bath or in the wash cycle of a laundry washing machine, the compositions contain an anionic and/or a nonionic surfactant.
Among the anionic surface active compounds useful in the present invention are those surface active compounds which contain an organic hydrophobic group containing from about 8 to 26 carbon atoms and preferably from about 10 to 18 carbon atoms in their molecular structure and at least one water-solubilizing group selected from the group of sulfonate, sulfate, carboxylate, phosphonate and phosphate so as to form a water-soluble detergent.
Examples of suitable anionic detergents include soaps, such as, the water-soluble salts (e.g., the sodium potassium, ammonium and alkanol-ammonium salts) of higher fatty acids or resin salts containing from about 8 to 20 carbon atoms and preferably 10 to 18 carbon atoms. Particularly useful are the sodium and potassium salts of the fatty acid mixtures derived from coconut oil and tallow, for example, sodium coconut soap and potassium tallow soap.
The anionic class of detergents also includes the water-soluble sulfated and sulfonated detergents having an aliphatic, preferably an alkyl radical containing from about 8 to 26, and preferably from about 12 to 22 carbon atoms. Examples of the sulfonated anionic detergents are the higher alkyl aromatic sulfonates such as the higher alkyl benzene sulfonates containing from about 10 to 16 carbon atoms in the higher alkyl group in a straight or branched chain, such as, for example, the sodium, potassium and ammonium salts of higher alkyl benzene sulfonates, higher alkyl toluene sulfonates and higher alkyl phenol sulfonates.
Other suitable anionic detergents are the olefin sulfonates including long chain alkene sulfonates, long chain hydroxyalkane sulfonates or mixtures of alkene sulfonates and hydroxyalkane sulfonates. The olefin sulfonate detergents may be prepared in a conventional manner by the reaction of SO3 with long chain olefins containing from about 8 to 25, and preferably from about 12 to 21 carbon atoms, such olefins having the formula RCHxe2x95x90CHR1 wherein R is a higher alkyl group of from about 6 to 23 carbons and R1 is an alkyl group containing from about 1 to 17 carbon atoms, or hydrogen to form a mixture of sultones and alkene sulfonic acids which is then treated to convert the sultones to sulfonates. Other examples of sulfate or sulfonate detergents are paraffin sulfonates containing from about 10 to 20 carbon atoms, and preferably from about 15 to 20 carbon atoms. The primary paraffin sulfonates are made by reacting long chain alpha olefins and bisulfites.
Other suitable anionic detergents are sulfated ethoxylated higher fatty alcohols of the formula RO(C2H4O)mSO3M, wherein R is a fatty alkyl of from 10 to 18 carbon atoms, m is from 2 to 6 (preferably having a value from about ⅕ to xc2xd the number of carbon atoms in R) and M is a solubilizing salt-forming cation, such as an alkali metal, ammonium, lower alkylamino or lower alkanolamino, or a higher alkyl benzene sulfonate wherein the higher alkyl is of 10 to 15 carbon atoms. The proportion of ethylene oxide in the polyethoxylated higher alkanol sulfate is preferably 2 to 5 moles of ethylene oxide groups per mole of anionic detergent, with three moles being most preferred, especially when the higher alkanol is of 11 to 15 carbon atoms. A preferred polyethoxylated alcohol sulfate detergent is marketed by Shell Chemical Company as Neodol 25-3S.
The most highly preferred water-soluble anionic detergent compounds are the ammonium and substituted ammonium (such as mono, di and tri ethanolamine), alkali metal (such as, sodium and potassium) and alkaline earth metal (such as, calcium and magnesium) salts of the higher alkyl benzene sulfonates, olefine sulfonates and higher alkyl sulfates. Among the above-listed anionics, the most preferred are the sodium linear alkyl benzene sulfonates (LABS), and especially those wherein the alkyl group is a straight chain alkyl radical of 12 or 13 carbon atoms.
Any suitable nonionic detergent compound may be used as a surfactant in the present compositions, with many members thereof being described in the various annual issues of Detergents and Emulsifiers, by John W. McCutcheon. Such volumes give chemical formulas and trade names for commercial nonionic detergents marketed in the United States, and substantially all of such detergents can be employed in the present compositions. However, it is highly preferred that such nonionic detergent be a condensation product of ethylene oxide and higher fatty alcohol (although instead of the higher fatty alcohol, higher fatty acids and alkyl[octyl, nonyl and isooctyl]phenols may also be employed). The higher fatty moieties, such as the alkyls, of such alcohols and resulting condensation products, will normally be linear, of 10 to 18 carbon atoms, preferably of 10 to 16 carbon atoms, more preferably of 12 to 15 carbon atoms and sometimes most preferably of 12 to 14 carbon atoms. Because such fatty alcohols are normally available commercially only as mixtures, the numbers of carbon atoms given are necessarily averages but in some instances the ranges of numbers of carbon atoms may be actual limits for the alcohols employed and for the corresponding alkyls.
The ethylene oxide (EtO) contents of the nonionic detergents will normally be in the range of 3 to 15 moles of EtO per mole of higher fatty alcohol, although as much as 20 moles of EtO may be present. Preferably such EtO content will be 3 to 10 moles and more preferably it will be 6 to 7 moles, e.g., 6.5 or 7 moles per mole of higher fatty alcohol (and per mole of nonionic detergent). As with the higher fatty alcohol, the polyethoxylate limits given are also limits on the averages of the numbers of EtO groups present in the condensation product. Examples of suitable nonionic detergents include those sold by Shell Chemical Company under the trademark Neodol(copyright), including Neodol 25-7, Neodol 23-6.5 and Neodol 25-3.
Other useful nonionic detergent compounds include the alkylpolyglycoside and alkylpolysaccharide surfactants, which are well known and extensively described in the art.
The preferred alkyl polysaccharides for use herein are alkyl polyglucosides having the formula
RO(CnH2nO)r(Z)x
wherein Z is derived from glucose, R is a hydrophobic group selected from the group consisting of alkyl, alkylphenyl, hydroxyalkylphenyl, and mixtures thereof in which said alkyl groups contain from about 10 to 18, preferably from about 12 to about 14 carbon atoms; n is 2 or 3 preferably, 2; r is from 0 to 10, preferably 0; and x is from 1.5 to 8, preferably from 1.5 to 4, most preferably from 1.6 to 2.7. To prepare these compounds, a long chain alcohol (R2OH where R2 is an alkyl group of about C10 to C18) can be reacted with glucose, in the presence of an acid catalyst to form the desired glucoside. Alternatively, the alkyl polyglucosides can be prepared by a two step procedure in which a short chain alcohol (R1OH wherein R1 is an alkyl having from 1 to 6 carbon atoms) is reacted with glucose or a polyglucoside (x=2 to 4) to yield a short chain alkyl glucoside (x=1 to 4) which can in turn be reacted with a longer chain alcohol (R2OH) to displace the short chain alcohol and obtain the desired alkyl polyglucoside. If this two step procedure is used, the short chain alkylglucoside content of the final alkyl polyglucoside material should be less than 50%, preferably less than 10%, more preferably less than about 5%, most preferably 0% of the alkyl polyglucoside.